PokerSolver
PokerSolver/4-max · 100bb · SB 0.5bb · 5% rake, cap 3bb/BTN vs CO open 2.5bb

BTN vs CO open 2.5bb

4-max · SB 0.5bb · 5% rake, cap 3bb (blinds 0.5/1bb) · 100bb · CO opens 2.5bb · Button to act

4-max · 100bb · SB 0.5bb · 5% rake, cap 3bbChange game
Stacks (bb), if they differ
Pot 4bbYour cards?
0.5bb
1bb
2.5bb

Tap your two cards.

Button's range

1,326 of 1,326 combos get here
Fold 84%Call 1.3%Raise 5/7.5bb 14.7%
Tap a hand, or type one above, to see its exact mix.

What is the GTO play for the button (BTN) when CO opens 2.5bb in 4-max · SB 0.5bb · 5% rake, cap 3bb at 100bb?

CO opens 2.5bb in 4-max · SB 0.5bb · 5% rake, cap 3bb, 100bb: the button (BTN) folds 84%, calls 1.3% and raises 5/7.5bb 14.7%. Always raise 5/7.5bb: TT+, 88, AJs+, A5s, KJs+, K9s, QJs, JTs, T9s, 65s, AQo+. Mixed: 99, 44-77, A6s-ATs, A3s-A4s, KTs, K8s, Q9s-QTs, J9s, 98s, 87s, 76s, 54s, ATo-AJo, KJo+, QJo.

Always fold
22-33, A2s, K2s-K7s, Q2s-Q8s, J2s-J8s, T2s-T8s, 92s-97s, 82s-86s, 72s-75s, 62s-64s, 52s-53s, 42s+, 32s, A2o-A9o, K2o-KTo, Q2o-QTo, J2o+, T2o+, 92o+, 82o+, 72o+, 62o+, 52o+, 42o+, 32o
Always call
No hand plays this every time
Always raise 5/7.5bb
TT+, 88, AJs+, A5s, KJs+, K9s, QJs, JTs, T9s, 65s, AQo+
Mixed
99, 44-77, A6s-ATs, A3s-A4s, KTs, K8s, Q9s-QTs, J9s, 98s, 87s, 76s, 54s, ATo-AJo, KJo+, QJo
Settings: 4-max · 100bb · SB 0.5bb · 5% rake, cap 3bb (small blind 0.5bb, big blind 1bb, 100bb stacks, 5% rake capped at 3bb; before the flop, rake only after a 3-bet). Solver: HoldemResources Calculator (HRC) (HRC CI 20.31). A jackpot fee on bigger pots is not in this solve, so lines that build big pots may be slightly too loose. Bet sizes are the solved ones; a size that is not here plays like the nearest one.

Fits exactly: no game we have checked.

Close: GGPoker regular cash NL50 (rake cap 6bb there, 3bb here).

Close: GGPoker regular cash NL100 (rake cap 3.75bb there, 3bb here).

Close: GGPoker regular cash NL200 (rake cap 2.25bb there, 3bb here).

Close: PokerStars cash NL50 (rake cap 1.5bb there, 3bb here; no rake when no flop is dealt there).

Close: CoinPoker cash NL2, NL10 (rake cap 6bb there, 3bb here; only its tables without antes).

Close: CoinPoker cash NL50 (rake cap 4.8bb there, 3bb here; only its tables without antes).

Close: CoinPoker cash NL100 (only its tables without antes).

Close: CoinPoker cash NL200 (rake cap 1.8bb there, 3bb here; only its tables without antes).

Close: WPT Global cash NL10, NL20 (4% rake there, 5% here; no rake when no flop is dealt there; only its tables without antes).

Close: WPT Global cash NL100, NL200 (rake cap 2bb there, 3bb here; 4% rake there, 5% here; no rake when no flop is dealt there; only its tables without antes).

Close: Natural8 regular cash NL50 (rake cap 6bb there, 3bb here).

Close: Natural8 regular cash NL100 (rake cap 3.75bb there, 3bb here).

Close: Natural8 regular cash NL200 (rake cap 2.25bb there, 3bb here).

Close: ACR Poker cash NL50 (rake cap 4bb there, 3bb here; its page does not say whether pots that end before the flop are raked).

Close: ACR Poker cash NL100 (rake cap 2bb there, 3bb here; its page does not say whether pots that end before the flop are raked).

CoinPoker tables with antes: their own chart.

Rake sources: ggpoker.com/poker-games/texas-holdem (fetched 2026-10-31); Rush rake and preflop rake confirmed on our own GG exports (972 of 1,034 pots, 210 of 211); regular tables' preflop rule from natural8.com/en/poker/texas-holdem (same network, fetched 2026-10-31); pokerstars.com/poker/room/rake (fetched 2026-10-31); coinpoker.com/games/texas-holdem/ (caps and the preflop rule) and coinpoker.com/guides/poker-rake/ (5%), fetched 2026-10-31; wptglobal.com/poker/poker-table-rake (fetched 2026-10-31); natural8.com/en/poker/texas-holdem (fetched 2026-10-31; caps by players dealt in, 3-bet pots raked before the flop); acrpoker.eu/real-money/poker-rake-calculation/ (fetched 2026-10-31).

Rake: Wrong rake for GG: this solve caps the rake at 3bb, but GG caps NL200 at $4.50 (2.25bb) with 4 players dealt in and $3 (1.5bb) with 3. A solve with GG's caps is queued.